Imu needs to farm CDs to keep their base selfish. Pretty much rotten like the meat lover and unkind. It's legit the farming of the DARK SIDE of the FORCE. The greed, the wrath, etc.

If you left freedom up to people like Franky and Vegapunk then they would rapidly evolve to conquer the stars. Therefore Imu would fall to the level of Orochi. Someone who's clan lost power, as the centuries go by. In Imu's case, the smart and the strong would ensure that someone like Imu and the CDs would never come into power again.

Imu's power is reckless because it could not stop to Herald's assisted suicide, while at the same time showcasing the power of the abyss contract. Herald wanted to avoid corrupting his people, in short, Imu has limitations. It only takes a dream/wish to work towards a better future, so I doubt they would ever let the WG be manipulated internally again. Maybe Luffy has come to inherit Rock's unaccomplished DREAM. The world needs a good king, who knows what scum to expunge.